Drupal Inclusion of Functionality from Untrusted Control Sphere Vulnerability - CVE-2017-6381
A 3rd party development library including with Drupal 8 development dependencies is vulnerable to remote code execution. This is mitigated by the default .htaccess protection against PHP execution and the fact that Composer development dependencies aren39t normal installed. You might be vulnerable to this if you are running a version of Drupal before 8.2.2. To be sure you aren39t vulnerable you can remove the ltsiterootgt/vendor/phpunit directory from your production deployments